Variable speed power transmission mechanism



June 1,1943. K. G. DETHRIDGE 2,320,854

VARIABLE SPEED POWER TRANSMISSION MECHANISM Filed Sept. 17, 1940ZSheets-Sheet 2 INVENTOR KENNETH GEORGE DETHRIDGE M, Qw

ATTORNEYS Patented June 1, 1943 VARIABLE SPEED POWER TRANSMlSSlONMECHANISM Kenneth George Dethridge, South Yarra, near Melbourne,Victoria, Australia Application September 17, 1940, Serial No. 357,168

In Australia October 23, 1939 19 Claims.

This invention relates to improvements in variable speed powertransmission mechanisms. In particular, it refers to an improved powertransmission gearing, braking and clutch mechanism which provides aninfinite and continuous range of gear ratios between a driving and adriven shaft such as, for example, between the shaft of an internalcombustion engine and the propeller shaft leading to the differentialgear of an automobile. Consequently, the driven shaft, for a setrotational speed of the driving shaft with variable power, will have acontinuous and variabl range of speeds and a variable power output.

It is an object of the invention to provide an automatic gear mechanismof such construction that the ratio of gearing between a driving and adriven shaft will be variable without the necesity of altering therelative arrangement and disposition of the gear integers.

A further object of the invention is to provide a power transmissionmechanism of such construction that it functions as a flexible couplingto prevent undue straining of the parts in the event of a suddenstoppage of either the driving or driven, shafts.

A still further object is to provide a power transmission mechanismwhich will automaticale ly apply a braking force to the driven shaft soas to decrease its rotational speed should the driven shaft increase itsrotational speed to such an extent that it overruns th driving shaft.

To achieve the objects hereinbefore recited, an arrangement of gearscomprising an epicyclic gear mechanism which is operatively connected toone or more elements so arranged and mount ed that the said elementswill pulsate with damped vibratory movements. The latter mechanismthroughout the following description and claims is termed an inertiamechanism.

Reference is now made to the accompanying drawings, wherein:

Fig. 1 illustrates in plan view one embodiment of the invention.

Fig. 2 is a fragmentary plan view, partly in section, of the mechanismillustrated in Fig. 1.

Fig. 3 is a view in side elevation of the inertia mechanism seen inFigs. 1 and 2.

Fig. 4 illustrates in side elevation the secondary or driven portion ofthe epicyclic gearing shown in Figs. 1 and 2.

Fig. 5 is a view illustrating an alternative arrangement of epicyclicgearing.

Fig. 6 is a sectional view showing a further alternative arrangement ofepicyclic gearing.

Fig. '7 is a view in side elevation of an alternative type of inertiamechanism.

Figs. 8 and 9 are views in plan and in side elevation, respectively, ofanother type of inertia mechanism.

Fig. 10 shows a further type of inertia mechamsm.

Referring initially to Figs. 1 to 4, ll designates the shaft of aninternal combustion engine or other power source (hereinafter termed theengine shaft) and I2 the driven or propeller shaft which is mounted inco-axial alignment with said shaft l I. Fixed on the engine shaft is aprimary driving gear wheel l3 and freely mounted on said engine shaftadjacent to the wheel i3 is a primary transmission gear wheel it havingtwo coaxial sets of teeth 15 and I6 constructed as an integral unit, anda bearing sleeve H.

A driven gear wheel [8 is fast on the propeller shaft 12 closelyadjacent to the driving gear wheel l3, and journaled on said propellershaft is a gear wheel I9 having a bearing sleeve 20, circumferentialgear teeth 2! and a brake drum 22 for engagement by an external brakeband 23 of conventional design and operation. The gear wheel has thesame diameter as that of the gear I 5 of the primary transmission gearwheel IS. A plurality of spindles 24 parallel with the shafts I I and I2are carried by said gear wheel l9, and on each spindle there isjournaled a combination gear wheel 25 comprising an intermediate gearwheel 26 and end gear wheels 21 and 28, the pitch circle diameter ofgear wheel 21 being greater than that of gear wheel 28, and the diameterof gear wheel 26 being greater than that of gear wheel 21 for thepurpose to be hereinafter explained. The intermediate gear wheel 26 isin mesh with the driving gear wheel 13: the end gear wheel 21 is in meshwith the teeth I5 of the transmission gear wheel I4: and the end gearwheel 28 meshes with the driven gear wheel iii.

A shaft 29 is rotatably mounted in bearings 30 parallel with the engineand propeller shafts ll and I2 and slidably but not rotatably fittedthereon is a gear wheel 3! having a shift collar 32 operated. by a shiftfork 33. The gear wheel 3| can be slidably moved on said shaft 29 sothat it engages with either of the transmission gear wheels I5 or 2|which are rotatable about the engine shaft II and the propeller shaft,respectively. Secured on the shaft 29 are plates 34 having eccentrics 35to which connecting rods 36 are fitted at one end. The opposite end ofeach connecting rod is coupled by a cross-pin 3'! to upwardly projectinglugs 33 of a slide 39 which a 49 of a fly-wheel 4|.

is adapted to travel circumferentially on the rim Each fly-wheel isrotatably mounted on a horizontal shaft 42 carried by brackets 43, andit has peripherical flanges 44 formed integrally with its rim 49 so thatthe slide 39 can travel freely in the guides which are formed thereby.

A rod 45 of circular cross-section which is almost completely circularin form is secured to the fiy-wheel 4|. The opposite ends of said rodare clamped by blocks 46 bolted to the rim 40 and by set-screws 41. Therod 45 concentrically encircles the rim 40 of the fiy-wheel 4|, and itpasses through a guide hole 48 formed in the slide 39see Fig. 21.Consequently, the rod 45 acts as a guide for said slide to retain thesame in sliding contact with the rim of said fiy-wheel. Two stronghelical springs 49 are positioned about the circular rod 45 and they areconnected at their opposite ends by bolts 50 to the clamping blocks 46and to the slide 39 so that movement of said slide in its guidewaysrelative to the fly-wheel 4| will set up compressional and tensionalforces in the springs 49 whereby said fly-wheel will be caused torotate.

Upon rotation of the engine shaft II in clockwise direction, by way ofexample, each of the combination gears 25 is caused to rotate in ananti-clockwise direction by reason of the engagement of eachintermediate gear wheel 26 with the driving gear wheel l3. Thetransmission gear wheel l4 and the driven gear wheel l8 are both causedto rotate in clockwise direction relative to said combination gears 25and the gear wheel|9 which carries the spindles 24. If the sliding gearwheel 3| be moved into engagement with the teeth 2| of the gear wheel I9so that the variable brake acts in the manner to be hereinafterdescribed upon said gear wheel l9, power will be transmitted from thedriving gear wheel l3 through the intermediate gear wheel 26 and thegear wheel 28 to the driven gear wheel I8 and the transmission gearwheel l4 will continue to rotate freely in a clock wise direction.Therefore, the drive of the propeller shaft |2 and the engin shaft II isunidirectional and the mechanism is in forward gear.

Upon disengagement of the gear wheel 3| from the gear teeth 2|, the endgear wheels 28 revolve on the stationary gear wheel l8 and thereby causethe gear wheel l9 to rotate in anticlockwise direction. By reason of theratio of teeth of the gear wheels 21 and 28 of the combination gear 25,the primary transmission gear wheel M will rotate in clockwisedirection. If the sliding gear wheel 3| is now engaged with the gearteeth l so as to brake the primary transmission gear wheel Hi, theanti-clockwise rotation of the combination gear wheels 25 about theirspindles 24 caused by the clockwise rotation of the engine shaft H andprimary gear l3 will produce anti-clockwise rotation of the gear wheell9 supporting said combination gear wheels 25. In consequence, thedriven gear wheel I8 is acted upon by the gear wheels 28 which arerotating on the spindles 24 and are revolving about the shaft l2. Theclockwise motion caused by the revolution of the gear wheels 28 aboutthe shaft |2 is greater than the clockwise motion caused by the rotationof said gear wheels 28 about their spindles 24. The gear wheel l8 andthe propeller shaft l2, therefore, will be driven in a reverse directionat a speed dependent upon the diil'erence of speeds of said gear wheelsI9 and 28.

When the gear wheel 3| which is slidably mounted on the shaft 29 is inoperative engagement with either of the sets of gear teeth |52|, theplates 34 are rotated, and through the eccentrics 35 and connecting rods36, the slides 39 are compelled to travel on the rims 40 of theirrespective fly-wheels 4| with substantially reciprocatory motion. Uponthe movement of each slide 39, it compresses one of the helical springs49 and extends the other of said springs and the compressional andtensional forces of the springs thus set up act upon the fly-wheel 4| torotate it.

The reciprocatory motion of the slide is relatively fast. By the timethe inertia of the flywheel has been overcome in one direction by theforces of the springs, said slide is at the end of its forward movementand consequently, upon its travelling in a reverse direction there areset up tensional and compressional forces in the springs to rotate saidflywheel in the opposite direction. In consequence, each flywheel 4| isset into oscillatory motion and the pulsating kinetic energy thusdeveloped builds up a back pressure to prevent the reciprocatory motionof the slide 39, thereby acting as a brake upon the shaft 29, the gearwheel 3| and relative gear l5 or 2|. It is to be noted that the fasterthe motion of the slide 39, the greater is the arc of oscillation of theflywheel 4| and the greater is the back pressure created and inconsequence the greater is the power that is transmited to the drivengear wheel l8. It is to be further noted that for a uniform speed ofrotation that is transmitted to the shaft l2, the oscillatory motion ofthe flywheel 4| will be constant, and that for a variable power outputthe braking effect of the inertia mechanism will be variable so thatthere is provided a continuous and infinite range of gear ratios betweenthe engine shaft II and the propeller shaft l2.

When the sliding gear 3| is in mesh with the gear teeth 2| of the gearwheel |9 so that the mechanism is in forward gear, it may be desirableto eliminate the effect of the inertia mechanism when a substantiallyuniform speed of rotation is being imparted to the propeller shaft l2and substitute for the variable brake a fixed brake.

For the purpose mentioned, the brake drum 22 and the brake band 23 areprovided. As the uniform speed is approached, the transmission of powerfrom the engine to the driving gear wheel I3 is temporarilydiscontinued, whereupon the movement of the inertia mechanism will ceaseand the gear wheel l9 will become substantially stationary. Then thebrake band 23 is tightened or clamped about the brake drum 22 and theclutch is re-engaged to permit the transmission of power to the drivinggear wheel l3. The result is that a definite fixed brake has beenapplied to the gear wheel l9 in place of the variable brake set up bythe inertia mechanism, and the power that is transmitted to thepropeller shaft i2 i entirely dependent upon the power transmitted bythe engine shaft H and independent of the resistance to be overcome tothe rotation of the shaft I2.

According to the embodiment illustrated by Fig. 5, the engine shaft Hhas a driving gear wheel I3 secured at one end thereof and adjacent 54,respectively. Formed integrally with said gear wheel are a gear wheel 55and a brake drum :2 and about this brake drum there is fitted J a brakeband 23 adapted for operation in customary manner.

A gear wheel I9 having a bearingsleeve and circumferential teeth 2| isrotatably mounted at the end of the propeller shaft I2 adjacent thedriving'gear wheel I3 and said gear wheel I9 carries a plurality ofoutwardly projecting spindles 24 in parallel arrangement with the shaftsII and I2. On each spindle there is Journaled a gear wheel 56 adapted tomesh with -the driving gear wheel I3 and the internal teeth 53 of thegear wheel 5|. The pitch circle diameters of the gear 2| of'the gearwheel I9 and the external gear 54 of the gear wheel 5| are the. same.

One member 51 or a. dog clutch is formed integrally with the gear wheelI9 and the opposite clutch member 58 is formed integrally with a largegear wheel 69 having a shift collar 69 for operation by a shift fork 6|.The combination unit comprising the gear wheel 59, collar 60 and clutchmember 59 is slidably but non-rotatably mounted upon the propeller shaftI2 so that when the clutch 51-56 is engaged the gear wheel I9 transmitspower to said propeller shaft.

A secondary shaft 62 is journaled in bearings parallel to the shafts IIand I2 and fixed thereon is a gear wheel 63 adapted to mesh with thegear wheel 59 upon disengagement of the clutch 5'I56 and a gear wheel 64which is constantly in mesh with the teeth 55 of the gear wheel 5|. Theshaft 29, whereon is slidably mounted the gear wheel 3| which is adaptedto engage either of the gears 54 or 2| is, for convenience ofillustration, shown disposed opposite the secondary shaft 62. The shiftfork 33 for operating said gear wheel 3| is linked with the shift fork6| which operates the gear wheel 59 and clutch 59 so that one movementofa gear handle will simultaneously disengage the clutch 56-51, engagethe gears 5963, and shift the inertia brake from the gear teeth 54 togear teeth 2|, or vice versa as may be required.

As previously indicated, the shaft 29 is, for con-- venience, shown in aposition opposite the shaft 62. However, in actual construction, theparts may be otherwise arranged about the axis of the shafts II and I2.The inter-connection between the shift forks 33 and 6| has not beenshown since they may be inter-connected in any suitable fashion forsimultaneous operation by a single shift lever. Since variousarrangements may be employed for thus inter-connecting the shift forks33 and GI, it is believed that specific illustration of the same isunnecessary.

When the gears 59-63, 64-55 and 3I-2I are engaged and the clutch 56-51is disengaged, the mechanism is in reverse and power is transmitted fromthe engine shaft II to the propeller shaft I2 in reverse direction. Upondisengagement of the gears 5963, engagement of the clutch 58-51 andmovement of the inertia brake gear 3| from the circumferential teeth 2|of the gear wheel I9 to mesh with the external teeth 54 of the gearwheel 5| the mechanism is placed into/ forward gear.

It will be observed that in the construction illustrated gears 64 and 55are constantly in mesh, it being unnecessary to disengage these pellershaft I2 mounted in co-axial alignment! A driving gear wheel I3 is fixedat the end of the engine shaft II and a. driven gear wheel I8 is securedat the end of the propeller shaft I2. A wheel I9 having a bearing sleeve20 is rotatably mounted on the engine shaft II close to the gear wheelI3 and it carries a plurality of outwardly projecting spindles 24 inparallel arrangement with the shafts I and I2. On each spindle there isjournaled a gear wheel 56 adapted to mesh with the driving gear wheel I3and the internal teeth 53 of a gear wheel 5| which'is rotatably andslidably mounted on the engine shaft II closely adjacent to the wheelI9. The gear wheel on the shaft 29 and operatively connected to theinertia mechanism. Also rotatable on the spindles 24 are combinationgear wheels 66, each consisting of a gear 61 of the same diameter as thegear wheel 56 and a smaller gear 66. The gears 61 are in mesh with thedriven gear wheel I8 and with the internal gear teeth 69 of a ring orhoop gear wheel 10 which has a side flange 1| fitting close to the sideof the gear 61 and encircled by a brake band 12 adapted to be clampedabout its outer surface. The gears 68 of the combination gear wheels 66engage with the gear teeth 13 of a gear wheel 14 which has a bearingsleeve 15 and is rotatably mounted upon the propeller shaft I2. Theouter surface 16 of gear wheel 14 is encircled by a brake band 11adapted to be operated in customary manner.

The mechanism is put into reverse gear by clamping the brake band 11about the brake surface 16 to hold the gear wheel '14 stationary Thenthe driving gear wheel I3, rotating in a clockwise direction, turns thegear wheels 56 independently in anti-clockwise direction about theirspindles 24. Owing to the variable brake which is applied to the gearwheel 5|, said gear wheels 56 run as a group on the internal teeth 53 ofsaid gear wheel 5| so that the wheel I9 rotates in clockwise direction.The clockwise rotation of the wheel I9 causes clockwise rotation of thecombination gear wheels 66 as the smaller gears 68 thereof mesh with theteeth 13 of the gear wheel 14. The anti-clockwise rotation of the drivengear wheel I8 caused by the clockwise rotation of the gear 66 about thespindles 24 is greater than the clockwise rotation that would be set upin said gear wheel I9 by the clockwise rotation of the wheel I9 if saidgears 66 were motionless. Consequently, the driven gear I8 is turned inanti-clockwisedirection and the mechwheel 5|, as in reverse gear, tocause the wheel 19 to rotate in clockwise direction and that clockwiserotation causes the gears 81 of the combina tion gear wheels 93 to runon the internal teeth 59 of the braked ring gear wheel 10.

. When the mechanism is operating ata uniform speed, a fixed drive canbesubstituted forthe variable drive by sliding the gear-whee1 5i alongthe engine shaft ll so that the internal teeth 53 engage thegears 61 aswell as the gear wheels. 55 so that'the external teeth 54 disengage fromthe gear wheel 3| .and inertia mechanism. At the same time the brakeband 12 about the ring gear wheel must be unclamped.

Modified constructions of apparatus for set-' ting up damping effects ofvibratory movements are illustrated by Figs. '7 to 10. Reference beingmade to Fig. '7, the connecting rod 39 is mounted at one end on aneccentric 35 turning about a shaft 29, and its opposite end is connectedat 18 to a bar 19 which is pivotally suspended at its upper end to aslide 39 and has a weight 89 at its lower end. The slide 39 is movablein guides 44 and is acted upon by strong helical springs 49 having theiropposite ends anchored to the slide 39 and to blocks 46 secured to theguides 44. A rod 45 is fitted through the springs 49 and slide 39 andfastened to the blocks 46 to maintain said springs in operativeposition.

If the shaft 29 turns at such a speed that the connecting rod 36-causesthe pivotally suspended bar 19 to vibrate with its natural frequency, noback pressure, or damping will be created, but as the period ofvibration of the bar 19 decreases the slide 39 commences to move alongthe guides 44 against the forces of the springs 49 so that said bar 19pivots about an intermediate point instead of about its point ofsuspension and it oscillates with damped vibrations. Thus, there is setup a back pressure to prevent rotation of the shaft 29.

According to the modification shown in Figs.

8 and 9, a weighted slide 39 is movable longitudinally in guides 44 andhas a cage 8! which is pivotally mounted therein on pintles 8i a. Theconnecting rod 36, which is secured at one end to an eccentric 35,passes through the cage 8| and it has collars 82 secured at its oppositeend and at an intermediate point between the cage 8i and the eccentric35. Strong helical springs 49 are fitted about the rod 35 and have theiropposite ends secured to the cage 8| and collars 82.

Upon rotation of the eccentric 35 and connecting rod 36, the weightedslide 39 will be moved in the guides 44 by the action of the springs 49.but the phase difference between the movements of the connecting rod 36and slide 39 will be 90. Consequently, there will be damping of themovement of the connecting rod 36 and the shaft 29 whereon the eccentric35 is mounted will be subjected to a variable braking effect which isdependant upon the speed of rotation of said shaft.

According to the modification illustrated by Fig. 10, the slide 39 is ofhollow construction and is partially filled with a heavy liquid, such asmercury, indicated by 83. Upon movement of the slide 39 in reciprocatorymanner there will be slight lag in the movement of the liquid 83. Themovement of the liquid in one direction will therefore tend to preventmotion of the slide 39 as it commences to move back along its pathduring reciprocatory movement. That is to say. the movement of the slide39 will be damped.

What I at claim is:

1. An improved power transmission mechanism comprising, a shaft, afly-wheel on said shaft, 'a slide movable on the rim of the fly-wheel,sprin s connected to the slide and to the flywheel whereby movement ofsaid slide imparts rotational movement to said fly-wheel, and anepicyclic gear mechanism connected to said slide and adapted to impartvibratory movement to the latter.

2. An improved power transmission mechanism according to claim 1,wherein guidesfor the slide and the springs are provided on theperiphery of the fly-wheel, and wherein the slide is operativelyconnected to the epicyclic mechanism through an eccentric mechanism.

3. An improved power transmission mechanism comprising, fixed guides, aslide longitudinally movable in said guides, springs connected to theslide and to the guides, a bar pivoted at its upper end to the slide, aweight at the lower end of said bar and an epicyclic gear mechanismhaving one of its rotating elements operatively connected to said barthrough an eccentric mechanism. '4. An improved power transmissionmechanism comprising, fixed guides, a slide longitudinally movable insaid guides, a cage pivotally mounted in said slide, a rod passinglongitudinally through said cage, springs on said rod connected to saidcage, and an epicyclic gear mechanism having one of its rotatingelements operatively connected to said rod through an eccentricmechanism.

5. An improved power transmission mechanism comprising, fixed guides, ahollow slide longitudinally movable in said guides, a heavy liquid insaid slide, and an epicyclic gear mechanism having one of its rotatingelements operatively connected to said hollow slide through an eccentricmechanism.

6. An improved power transmission mechanism comprisig, a driving shaft,a driven shaft axially aligned with said driving shaft, a primary gearwheel fixed on said driving shaft, a primary gear wheel freely rotatableabout the common axis of said driving and driven shafts, a supporting'wheel rotatable about said common axis, spindles fixed to saidsupporting wheel, secondary gear wheels rotatable on said spindlesadapted to mesh with the fixed and the freely rotatable primary gearwheels, external teeth on the freely rotatable primary gear wheels, asubsidiary shaft, a gear wheel on said subsidiary shaft adapted to meshwith said external teeth, eccentrics on said subsidiary shaft, elementsconnected to said eccentrics so constructed and arranged that they willpulsate with damped vibratory movements upon rotation of saideccentrics, and means for transmitting motion from said supporting wheelto said driven shaft.

7.An improved power transmission mechanism according to claim 6 andwherein a fixed brake is substituted for the variable brake provided bythe inertia mechanism.

8. An improved power transmission mechanism according to claim 6,wherein the freely rotatable primary gear wheel is mounted on thedriving shaft and consists of two co-axial gears, one of smallerdiameter than the other, a fixed gear wheel is secured at the end of thedriven shaft, the secondary gear wheels consist of three gear wheels ofdecreasing diameters in mesh respectively with the fixed primary gearwheel,

the small gear wheel of the freely rotatable gear wheel and the fixedwheel on the driven shaft, and wherein the supporting wheel hasperipheral teeth and a brake drum.

9. An improved power transmission mechanism according to claim 6,wherein freely rotatable primary gear wheel has internal teeth to meshwith the secondary gear wheels, a relatively small diameter gear wheeland a brake drum formed integrally therewith; the supporting wheel isrotatable on the drum shaft and has a clutch member, a slidablereversing gear wheel having a complementary clutch member which isslidably but non-rotatably mounted on the driven shaft; and thesecondary shaft has fixed thereon two gear wheels to mesh with the smalldiameter wheel of said freely rotatable primary gear wheel and with saidreversing gear wheel upon disengagement of said clutch members.

10. An improved power transmission mechanism according to claim 6.wherein the tertiary gear wheel is fixed at the end of the driven shaft,a freely rotatable tertiary gear Wheel having a brake drum is mounted onthe driven shaft, two independent secondary gear wheels are rotatable oneach spindle carried by the supporting wheel, one of which meshes withthe fixed primary gear wheel and the other meshes with the fixedtertiary gear wheel and the freely rotatable tertiary gear wheel,. aring gear wheel is fitted about the second secondary gear wheel and hasa brake drum, and wherein the freely rotatable primary gear wheel hasinternal teeth to selectively mesh with the first-mentioned secondarygear wheel or with both of said secondary gear wheels simultaneously.

11. A transmission comprising a driving shaft and a driven shaft; anepicyclic gear train interconnecting said shafts, said t rain includinga rotatable member carrying the planetary gears of said train; meansoperative to impart selectively forward or reverse rotation to saiddriven shaft, said means including a gear fixedly mounted on said drivenshaft in engagement with the planetary gears of said train and a. brakeselectively operative to hold said rotatable member; and means operativeto selectively engage said rotatable member of said epicyclic gear trainand convert movement thereof to an oscillatory movement, said last namedmeans including a device operative to dampen said movements.

12. A transmission comprising a driving shaft and a driven shaft, anepicyclic gear train interconnecting said shafts, said epicyclic geartrain including two sun gears of different pitch diameters respectivelyconnected to said shafts, planet gears each having a plurality ofaxially spaced sections of different pitch diameter with the severalsections of the same pitch diameter on the respective planet gearsarranged in the same plane, the sun gear cn'one of said shafts in meshwith the planet gears in the plane which includes the axial sections ofgreatest pitch diameter, and the sun gear on said driven shaft in meshwith the planet gears in the plane which includes axial sections ofsmaller pitch diameter, a third sun gear in mesh with said planet gearsin a plane which includes axial sections having a pitch diameterintermediate of the pitch diameters in mesh with the sun gears on saiddriving and driven shafts, a rotatable carrier for said planet gears,reciprocable means selectively connectable with either said third sungear or said planet gear carrier, and means for dampening the vibratorymovement of said reciprocable means.

13. A transmission comprising a driving shaft,

a driving gear on said driving shaft, a driven shaft, a driven gear onsaid driven shaft, an epicyclic gear train having the planetary elementsthereof constantly in mesh with said driving gear, a rotary carrier forsaid planet gearing, an internal gear in mesh with said planet gears, areciprocable member, means for selectively conmeeting said reciprocablemember with said carrier and said internal gear, and means for dampeningthe vibratory movement of said reciprocable member.

14. A transmission comprising a driving shaft, a driving gear on saiddriving shaft, a driven shaft, a driven gear on said driven shaft, anepieyclic gear train having the planetary elements thereof constantly inmesh with said driving gear, a rotary carrier for said planet gearing,an internal gear in mesh with said planet gears. a counter-shaft drivenfrom said internal gear and carrying a spur gear adapted to mesh withsaid driven gear, reciprocable means, means for simul taneously engagingsaid reciprocable means with said carrier and meshing said spur gearwith said driven gear, and alternatively moving said spur gearrelatively out of mesh with said driven gear and connecting saidreciprocable means with said internal gear, and means for dampening thevibratory movement of said reciprocable means.

15. A transmission comprising a driving shaft, a driving gear on saiddriving shaft, a driven shaft, a driven gear on said driven shaft, anepicyclic gear train havingthe planetary elements thereof constantly inmesh with said driving gear, a rotary carrier for said planet gearing,an internal gear in mesh with said planet gears, a counter-shaft drivenfrom said internal gear and carrying a spur gear adapted to mesh withsaid driven gear, reciprocable means, means for simultaneously engagingsaid reciprocable means with said carrier and meshing said spur gearwith said driven gear, and alternatively moving said spur gearrelatively out of mesh with said driven gear and connecting saidreciprocable means with said internal gear, means for dampening thevibratory movement of said reciprocable means, and complementary jaws onsaid carrier and driven gear adapted to inner-"engage when said drivengear is out of mesh with said spur gear.

16. An improved variable speed transmission mechanism comprising adriving shaft; a driven shaft axially aligned with said driving shaft; adriving train of epicyclic gears comprising a primary driving gear wheelfixed on said driving shaft, a supporting wheel rotatable about thecommon axis of said driving and driven shafts, a plurality of spindlesfixed to said supporting wheel and extended parallel to said commonaxis, a gear wheel freely rotatable about said common axis, andplanetary gear wheels rotatably mounted on said spindles and inengagement with said freely rotatable gear wheel and with said drivinggear wheel; a driven gear non-rotatably mounted on said driven shaft;and means operatively connecting one of said wheels freely rotatableabout said common axis with said driven gear on said driven shaft, saidlast named means including an inertia mechanism operatively engaging thesaid selected wheel.

17. An improved variable speed transmission mechanism according to claim16 wherein the freely rotatable gear wheel is provided with two externalgears diflering in diameter; the supporting wheel is provided with anexternal gear; and each of the planetary gear wheels embodies threegears of decreasing diameter in mesh respectively with the fixed primarydriving gear wheel, the small gear of the freely rotatable gear wheel,and the fixed driven gear on the driven shaft.

18. An improved variable speed transmission mechanism according to claim16, wherein the freely rotatable gear wheel is provided with an externalgear and an internal gear; the supporting wheel is provided with anexternal gear and a clutch member; the non-rotatable driven gear isslidably mounted on the driven shaft and carries clutch member adaptableto engage the member carriedon the supporting wheel; and each planetarygear wheel carries a single gear which is in engagement with theinternal gear on the freely rotatable gear wheel.

19. An improved variable speed transmission mechanism according to claim16, wherein the freely rotatable gear wheel is provided with an externaland an internal gear; each planetary gear wheel carries a single gearwhich is in engagement with the internal gear of the freely rotatablegear wheel; and wherein the means connecting the driven gear on thedriven'shaft operatively with the freely rotatable supporting wheelcomprises gear elements rotatably mounted on the spindles carrying theplanetary gears, each of which gear elements carries a gear of largerand a gear of smaller diameter, a gear ring rotatably mounted about thecommon axis of the driven and driving shafts which ring is provided withan internal gear in engagement with the gears of larger diameter carriedby said gear elements, braking means operative to hold said gear ringagainst rotation, a wheel rotatably mounted about the driven shaft whichwheel is provided with an external gear in engagement with the gears ofsmaller diameter carried by said gear elements, and braking meansoperative to hold said last named wheel against rotation.

KENNETH GEORGE DE'I'HRIDGE.

